Users of text-based applications, such as those involving email and short message service (SMS), can visually review information and provide input based on the visual information. However, Text-to-Speech (TTS) systems are increasingly used to audibly provide the information that was once visually reviewed. As text is generated by these applications, it can be converted to speech that is then heard by the user. The user can then respond either verbally or using a peripheral device, such as a keyboard. The audible presentation of information can be used to implement more streamlined applications that can operate without certain hardware devices as well as be used in environments where distractions can be a problem, such as the use of displays in a vehicle.
However, successful use of TTS systems with text-based applications depends on a high-quality TTS system output. When users of the text-based applications can clearly understand the TTS system output, they are then more likely to successfully interact with the text-based applications successfully. And when the TTS system output is unclear, the users will struggle to successfully interact with the text-based application. When the TTS systems output speech, it would be helpful to assess the quality of speech before it is presented and change the output when the assessment indicates poor quality.